7
• SEI or SER Terminals. Sporlan SEI and SER type electric expansion valves are currently used for all
applications. There are 1596 nominal steps for entire valve stroke.
• Pressure Transducer is mounted at the evaporator suction header to measure saturated suction pressure in
absolute value but displayed in gauge pressure in PSIG. The suction pressure is converted to evaporating
temperature. The difference between outlet temperature and evaporating temperature is the true superheat
displayed as “SUPH”.
• Defrost Termination Temperature Sensor TS3 is mounted downstream of the distributor tube after the valve
and close enough to the evaporator coil to measure defrost termination temperature during defrost cylce. Figure
2 on the previous page shows the sensor locations of the evaporator and the controller.
• Outlet/Fan Cut-In Temperature Sensor TS1 is mounted on the suction line about 6” to 10” away from the
evaporator to measure outlet temperature during cooling cycle and to serve as evaporator fan cut-in temperature
sensor. The sensor is at a 2 or 10 o’clock position on the suction line. The default value of the fan cut-in
temperature is pre-set at 20
o
F for commercial refrigeration application.
• Room Temperature Sensor TS2 is typically mounted with a plastic tie at the drain pan on the side of the
evaporator return air. It is located around the middle of the evaporator to allow even air flow across it. If
necessary, it can be relocated to a spot with better representation of the cold room temperature.
• Four Digit LED Display is used to show status of the controller, set point values and temperatures.
• Green Amber and Red LED Status Indicators. The green LED will be on when the compressor relay is
energized. The green LED will blink when the air temperature is satisfied, but the compressor minimum run timer
or minimum off timer has not yet timed out. The red LED indicates a critical alarm has occurred (Low Pressure
alarm). The amber LED indicates all other alarms.
• Six Push Buttons are used to display set points and status as well as to reset operational parameters like room
temperature, defrost mode, number of defrosts, etc. Their functions can be also performed by using the TCP/IP
interface.
• Two 20 Amp, 240 VAC NC/NO Relays. One relay is used for the defrost heater when the heater load is less
than 20 amp. It will be wired to defrost heater contactor when heater load is over 20 amp or three phase heaters.
For a reverse cycle defrost system, it is wired to a 40VA transformer that provides 24VAC power to the
reversing valve solenoid coil. The other relay is used to switch evaporator fans ON and OFF. A fan contactor
will be used if the fan motor is lager than 10 amps or three phase or the voltage is different from control voltage.
• One 3 Amp, 240 VAC NC/NO Relay is used for the compressor contactor or liquid line solenoid.
• One 3 Amp, 240 VAC NC/NO Relay is an option for an external alarm system. The customer can decide what
type of a physical alarm is used. This relay is energized when the controller is powered on. Whenever the
controller gives an alarm, the relay will be de-energized. For example, a technician can connect a phone alarm
system to this relay. When there is an alarm, the alarm system can dial in his pager or cellular phone.
• One RJ-45, TCP/IP Ehternet Port is used for Peer to Peer system or an alternating system communication
requiring ethernet connection. It is also used to communicate with a Laptop, internal network, or the internet.
• Power Input 120 or 208/240 VAC. For 120 VAC input, jumper between pins 1 and 2 of ‘Voltage Jumper’ connector and
jumper between pins 3 and 4 of ‘Voltage Jumper’ connector. For 208/240 VAC input, jumper between pins 2 and 3 of
‘Voltage Jumper’ connector.
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